The invention is based on a priority application EP97291326.2 which is hereby incorporated by reference.
The invention relates to a peer-to-peer network comprising common peers providing the functionality of the network. A peer-to-peer network is based on computing power, bandwidth and other resources, said resources being distributed across many terminals and peers. The peers are equal members, thus there exists no client and server architecture in a peer-to-peer network. The peers are organized in a so-called overlay network, i.e., the peers maintain a set of links to all other peers in form of routing/finger tables. Structured peer-to-peer networks like CHORD have a defined structure, i.e., their routing and look-ups are well defined. The network protocol CHORD creates an overlay network topology based on Distributed Hash Tables. A peer-to-peer network is scalable with increasing number of peers whereby defined stabilization processes manage the rapid joining or leaving of peers. Peer-to-peer networks are used for the realization of Voice over IP and multimedia solutions due to low cost, self-configuration, robustness and scalability. Open, standardized, structured and self-organizing peer-to-peer networks form the basis of public telecommunications systems, collaboration/community services over Internet, voice/multimedia conferencing, instant messaging, push-to-talk applications, information/file sharing for carriers and enterprises.
Those peer-to-peer networks provided with a minimum centralized infrastructure has still several unresolved security problems. Today's peer-to-peer network architectures are either classified as restricted or use reputation mechanism to establish security and trust between the peers. In case of restricted applications the software code is encrypted to prevent abuses for the purpose of creating malicious code. The network architecture and the communication protocols are withheld from general circulation. Reputation mechanisms are either user-based where the peers rate other peers, or transaction-based, where the trust value is computed based on all transactions a peer has performed with other peers. Said established security mechanism can not be applied to open and standardized public telecommunication systems. Restricted applications require a close system because security can only be guaranteed as long as the secrets are kept secret. The use of reputation mechanisms was proposed and researched, but the security threats could not be resolved. Machine-to-machine reputation systems for a public communication system have to be based on the transaction and message behaviour of peers, not on the user's behaviour.
The self-organizing mechanism implemented in the peer-to-peer network creates a robust topology and ensures consistency of the stored data. The use of an intelligent security mechanism shall protect the peers, i.e., the network participants, the network topology and the stored data against malicious peers and the circulation of malicious code.